Attachment plug



July 21,, WEE, w A. L. BECKET 'ATTACHMENT PLUG Filed Jan. 27, 1928' I awvehtoz Patented July 21, 1931- UNITED STATES PATENT OFFICE Application filed January 27, 1928. Serial No. 249,810.

a This invention relates to an attachment plug inwhich the necessity of holding the electric wire to the terminals by means of screws may be dispensed with entirely, or,

when the screws or other means are used for attaching the wires to the terminals, the strain on the same is relieved because the wire is clamped b means of elements ofthe plug so that p on the cord will not be transmitted to the connectors. At the same time the danger of short circuit between the wires is materially lessened because insulation material is interposed between the ends of-the respective wires where they are attached to the metal terminals, and the ends of the wires are farther apart than is usual in devicesof this sort. Also, the danger of the wires becoming electrically detached from th terminals is lessened because the wires are retained in a slot between parallel walls that either side. a v The invention will be understood from the description in connection with the acprevent escape of the'wire to g5 companying drawings in which Fig. 1 is a perspective view partly broken away of the device with the parts separated, and Fig. 2 is a perspective view of a modified term of one of the details. i I I In the drawings reference character 1 indicates a cap of insulating material that has a cylindrical portion that is screw threaded internally, as indicated at 2, and 'a rounded or somewhat conically shaped portion that is provided with an opening 3 therethrough.

A plug 4 of insulating material that may be c lindrical in shape is externally threaded as shown at 5 and engages the threads 2 in the cap 1. T 's plug may be hollow if de- 0 sired. It is provided with slots orvrecesses 6 on opposite sides thereofextending axially to accommodate metal terminals 7 that are wide enough to fit the slots closely. Binding screws 8 for holding the bare ends 9 of the wire 10 in place pass through the metal terminals 7 into corresponding screw threaded holes'in the plug 4, so that the screws 8 not only keep the wires connected to the terminals 7 but also keep the terminals 7 securely in place. The diameter of the heads of the screws 8 is preferably the same as the width of the slots 6 so that the wires will notv move to such positions that the screws would not clamp them in place.

In the modification shown in Fig. 2 the metal terminals 12 corresponding to the terminals 7 are provided with bent-in portions 13 at one end thereof to lie along the lower endof the plug 4. This modification also shows another way by which the wires may be attached to the metal terminals. Each metal terminal may havea tongue 14 struck outwardly therefromto form a slit into which the end of the bare wire may be slipped and kept in place by friction. Any other convenient means such as solder, for example, may be used for keeping'the ends of the bare wires into electrical contact with the terminals and it isnot necessary for the terminals to be screwed in place in the slots or recesses in the plug 4.

In assembling the device the cord 10 is passed through the hole 3 in the cap 1 and the wires 9 separated and the insulation stripped off. The wires can be attached to the metal terminals 7 by means of the screws 8 or in any other convenient manner as the terminals are readily accessible with the plug 4: out of the cap 1. After the wires are attached the cap 1 is screwed'on until the surface 15 thereof presses the spread ends of the wires 9 firmly in contact with the bottom of the plug 4, thus relieving any strain on the connection of the terminals 7.

It is obvious that the wire 10 can be pulled with safety for the purpose of withdrawing the metal contact 7 from the sockets into which they have been inserted. The bare ends of the wires 9 are separated considerable distances and have solid insulating material interposed between them. The terminals 7 are securely held in the slots or recesses 6, and the portions thereof to which the wires 9 are connected are entirely covered with the insulating material of the cap 1 so as to protect the same both mechanically and electricall The device is more convenient to assemble than other devices of this sort and may be made smaller than wires to the -metal u threaded cap and a screw threaded plug interrupted along its outer periphery, electric terminals carried on the sides of'said' plug at the places where said threads are inter- .rupted, and electric wires clamped to said 20 terminals, said cap pressing against said wires and terminals.

' ALAN L. BEOKET. 

